DevTools: create help sub-menu

third_party/WebKit/Source/devtools/front_end/main/module.json

 {
     "extensions": [
         {
             "type": "@Common.AppProvider",
             "className": "Main.SimpleAppProvider",
             "order": 10
         },
         {
             "type": "@UI.ContextMenu.Provider",
             "contextTypes": [
@@ skipping 355 matching lines @@
             "className": "Main.ShowMetricsRulersSettingUI"
         },
         {
             "type": "context-menu-item",
             "location": "mainMenu/navigate",
             "title": "More tools",
             "subMenuId": "mainMenuMoreTools",
             "order": 80
         },
         {
+            "type": "context-menu-item",
+            "location": "mainMenu/footer",
+            "title": "Help",
+            "subMenuId": "mainMenuHelp",
+            "order": 30
+        },
+        {
             "type": "view",
             "location": "drawer-view",
             "id": "rendering",
             "title": "Rendering",
             "persistence": "closeable",
             "order": 50,
             "className": "Main.RenderingOptionsView"
         },
         {
             "type": "setting",
@@ skipping 53 matching lines @@
         "ExecutionContextSelector.js",
         "Main.js"
     ],
     "resources": [
         "errorWarningCounter.css",
         "remoteDebuggingTerminatedScreen.css",
         "renderingOptions.css",
         "targetCrashedScreen.css"
     ]
 }